Process for the sulfonation of aromatic hydrocarbons or their derivatives.



H. BULL. PROCESS FOR THE SULFONATJON 0F AROMATICLHYDROCARBONS 0R THEIR DERIVATIVES.

APPLICATIONAPILED SEPT-2. I916- LMYAWD 1 PatentedNov. 2J91Z i I 1 WM almmwroz 1 earner oruion.

HANS BULL, OF PHILADELPHIA, PENNSYLVANIA. J

PROCESS FOR THE SULFONATION OF AROMATIC HYDROCABBONS OR THEIR DERIVATIVES. I

Lei-7,499.

Specification of Letters Patent.

Patented Nov. 211, 191?.

Application filed September 2, 1916. Serial No. 118.185.

7 Too whom it may concern:

Be it known that I, HANS BULL, a subject of the Kin of Norway, and a resident of the city an county of Philadelphia, State of Pennsylvania, have invented a certain new and useful Process for the Sulfonation of Aromatic Hydrocarbons or Their Deri- 'vatives, of which the following is a specification.

My invention relates to a process for the contlnuous or intermittent sulfonation of aromatic hydrocarbons or their derivatives, accompanied by simultaneous extraction of the sulfonated product and has asits object an efficient and expeditious method for economically performing said operation.

In the following I have described, in connection with the accompanying drawings, a way of carrying out my process with a modification thereof, the principles of the the respective outlet pipes or connections.

Said pipes or connections may be suitably valve controlled as desired.

In Fig. 2, 6, 7 8, 9 and 10 indicate tanks or receptacles preferably arranged one above the other, so that they may be discharged by gravity serially from one to the other downward. 11 indicates a pipe entering tank 10at preferably a little abovethe middle portion. 12 is a pipe leading from the bottom of tank 10 to preferably a little above the middle of tank 9. '13 is a pipe leading from the bottom of tank 9 preferably a little above the middle of tank 8.

'14 is a pipe leading from the bottom of tank 8 to preferably a little above the middle of tank 7 15' is a pipe leading from the bottom of tank 7 to preferably somewhat above the middle of tank 6. 16 is a discharge pipe from the bottom of tank 6.

Pipes 11, 12, 13, 14, 15 and 16 are all suitably valve controlled.

17 is a pipe entering tank 6 near its bottom. 18 is a pipe leading from near the top of tank 6 to near the bottom of tank 7 19, is a pipe leading from near the top. of tank 7 to near the bottom of tank 8.' 20 is a pipe leading from near the top of tank 8 to near the bottom of tank 9. 21 is a pipe leading from near the top of tank 9 to near the bottom of'tank 10 and 22 is a discharge pipe from near the top of tank 10.

The process is not restricted to the sulfonation of any particular aromatic hydrocarbon or derivatives of the same nor to the use of any particular solvent therefor provided the solvent possesses the following properties. 1. That sulfuric acid of the strength used in the sulfonation is not appreciably soluble therein. 2. That the solvent be of lower specific gravity than' said sulfuric acid. 3. That the aromatic hydrocarbon or its derivative to be sulfonated be soluble in the solvent. 4. That the product of sulfonation be s'olubleln the solvent.

As illustrations of aromatic hydrocarbons which may be sulfonated in this process I would mention benzene which is preferably sulfonated in a solvent comprising an excess of benzene, and naphthalene which may be sulfonated in benzene as a solvent or in a solvent of the paraflin series, such as naphtha. Other solvents having'the properties mentioned above will readily suggest themselves to thosc skilled in the art.

I shall describe my process in connection with the sulfonation of benzene as an example, first taking up the process as it would be carried out in the apparatus illustrated by Fig. 1 and afterward as it would be carried out in the apparatus illustrated in Fig. 2.

In starting the process with the apparatus illustrated in Fig. 1, the receptacle 1 ma be partly filled with sulfuric acid, refera ly fuming sulfuric acid, through in et 2. The aromatic hydrocarbon to be sulfonated for example benzene, is then run in under pressure through inlet pipe 3, either alone or dissolved in some solvent possessing the properties set forth, and the receptacle is filled so that after reaction, the sulfonated product dissolved in an excess of the hydrocarbon itself or other suitable solvent runs out through outlet pipe 4. By reason of its lower specific gravity than the sulfuric acid, the hydrocarbon to be sulfonated or the hydrocarbon and its solvent pass upward through the sulfuric acid and the hydrocarbon and sulfuric acid are thus brought into intimate contact and thoroughly commingled with each other, reacting upon each other to form the sulfonic acid of the aromatic hydrocarbon or derivative thereof, undergoing treatment, in the illustrated case benzene sulfonic acid. As is more specifically set forth in U. S. Letters Patent Nos. 1,211,923 and 1,212,612 issued on January 9, 1917 and January 16, 1917, respectively, to Louis M. Dennis, the aromatic hydrocarbon such as benzene, if this is used alone, is introduced in excess and said excess over the amount reacting with the sulfuric acid, dissolves the resulting sulfonic acid from the mixture of sulfbnic acid and sulfuric acid, extracting the same simultaneously with its formation, and carrying it out through the outlet pipe 4:, the sulfonic acid being ,soluble in the said aromatic hydrocarbon while the sulfuric acid is not appreciably soluble'therein. As the formation of the sulfonic acid takes place in an excess of the aromatic hydrocarbon, the absorption or extraction of the sulfonic acid is immediate and the efficiency of the Dennis process so far as extraction goes, is insured and increased.

The aromatic hydrocarbon either alone or dissolved in .a suitable solvent may be continuously supplied tothe receptacle and the spent or somewhat spent sulfuric acid continuously withdrawn from the receptacle through the outlet 5 while fresh sulfuric acid of proper strength may be continuously charged into the receptacle through inlet 2 so that the process of sulfonation and simultaneous extraction may be carried out as a continuous one or the supply of aromatic hydrocarbon or hydrocarbon dissolved in a suitable solvent may be continued until the acid becomes too weak to properly re act in which case the supply of aromatic hydrocarbon or hydrocarbon dissolved in a suitable solvent may be cut off, the weak acid withdrawn and the receptacle charged afresh, in this instance the process being intermittent.

In the sulfonation of a hydrocarbon of the aromatic series in the apparatus shown in Fig. 2, as given in connection with the process carried out in the apparatus shown in Fig. 1, the tanks are all first filled with the aromatic hydrocarbon under ressure through pipe 11 and/ connecting pipes 18, 19, 20 and 21 (either alone or dissolved in a suitable solvehflQi-until the hydrocarbon or hydrocarbon in solution begin to flo'w out at pipe 22. Sulfuric'acid preferably fuming sulfuric acid, is then caused to enter tank- 10 through pipe 11 and flows thence serially downward through tanks 9, .8, 7, and 6 byv means of connecting pipes 12, 13, 14 and 15,

respectively and out through pipe 16. The

sulfuric acid, by reason of its greater density 7 as compared with the aromatic hydrocarbon or hydrocarbon in solution flows downward through the respective tanks against the ascending current of the aromatic hydrocarbon or hydrocarbon in. solution which, on the other hand, by reason of its loweridensity or specific gravity, passes upwardgtserially through the tanks and out through-the pipe 22. The hydrocarbon to be sulfonated and the sulfuric acid are thus brought in intimate contact and thoroughly commingled through the counter current flow and react uponeach other to form the sulfonic acid of the aromatic hydrocarbon undergoing treatment with simultaneous extraction of the sulfoni acid from the residual sulfuric .acid by the excess of the aromatic hydrocarbon present or by the solvent thereof. In this case, as in connection with the process described in connection with Fig. 1, the aromatic hydrocarbon may be introduced in excess or dissolved in a suitable solvent and said excess above the amount reacting with the sulfuric acid or said solvent dissolves the resulting sulfonic acid from the mixture of sulfonic acid and sulfuric acid extracting the same simultaneously with its formation and carrying it out through pipe 22, the

residual sulfuric acid flowing out through pipe 16 accompanied by a small amount of sulfonic acid if the extraction is not complete.

By the process as practised in connection with the apparatus shown in Fig. 2, a continuous sulfonation of the hydrocarbon with 165 simultaneous extraction of the sulfonic acid be used for any desired purpose. As is 120 obvious, the purer hydrocarbon meets first with the less concentratedsulfuric acid and the more strongly sulfonated hydrocarbon meets with the. more concentrated sulfuric acid in the usual counter-current way.

It is obvious that the number and arrangement of tanks and the manner of connection between them, may be varied to suit the con ditions and that the process is applicable to the sulfonation of any aromatic hydrocar- 130 nated and the sulfonated bon by either a continuous or an intermittent process which hydrocarbon or its sol-' any appreciable amount of the sulfuric acid,

and I do not restrict myself to any of the details hereinafter set forth nor to the sulfonationof any particular aromatic hydrocarbon further than the scope of the appended claims demands.

VVherein in the claims Irefer to an aromatic hydrocarbon, in which the sulfuric acid is not appreciably soluble or to an excess of aromatic hydrocarbon in which the sulfuric acid is not appreciably soluble or to extracting the sulfonation product in an ex cess of the aromatic hydrocarbon, I mean to include as well any other suitable solvent in which the aromatic hydrocarbon and the sulfonation product but not the sulfuric acid are soluble.

I claim.

1. A process for the simultaneous sulfonation of aromatic hydrocarbons or their derivatives and'the extraction of the sulfonated product, consisting in causing sulfuric acid and the substance to be sulfonated to react upon each other in the presence of a solvent in which said substance and. the sulfonated product are soluble but the sulfuric acid is not appreciably soluble and withdrawing the sulfonated product extractcd in said solvent.

2. A process for the simultaneous sulfonation of aromatic hydrocarbons or their derivatives and the extraction of the sulfonated product, consisting in causing sulfuric acid and the substance to be sulfonated to react upon each other in the presence of an organic solvent in which said substance and the sulfonated product are soluble but the sulfuric acid is not appreciably soluble and withdrawing the sulfonated product extracted insaid. solvent.

3. A process for the simultaneous-sulfonation of aromatic hydrocarbons or their derivatives and the extraction of the sulfonated product, consisting in causing sulfuric acid and the substance to be sulfonated to react upon each other in the presence of an organic solvent of lower specific gravity than that of the sulfuric acid at the strength used and in which the substance to be sulforoduct are solu ble while the sulfuric acid is not appreciably soluble, and withdrawing the sulfonated product extracted in said solvent.

4. A process for the simultaneous sulfonation of aromatic hydrocarbons or their derivatives and the extraction of the sulfonated product consisting in causing sulfuric acid and an aromatic hydrocarbon inwhich the sulfuric acid is not appreciably soluble to react upon each other in the presence of an excess of the aromatic hydrocarbon and withdrawing the sulfonated product extracted in an excess of the aromatic hydrocarbon.

5. A process for the continuous sulfonation of aromatic hydrocarbons or their derivatives, with simultaneous extraction of the sulfonated product consisting in continuously passingan excess of an aromatic hydrocarbon in which sulfuric acid is not appreciably soluble through sulfuric acid and continuously removing the extracted sulfonated product in an excess of the aromatic hydrocarbon.

6. A process for the continuous sulfonation of aromatic hydrocarbons or their derivatives with simultaneous extraction of the sulfonated product consisting in assing an excess of an aromatic hydrocar on in which sulfuric acid is not appreciably soluble through sulfuric acid, continuously withdrawing the extracted sulfonated product in an excess of the aromatic hydrocarhonjl and continuously withdrawing the spent ac1 7. A process for the continuous sulfonation of aromatic hydrocarbons or their derivatives consisting in causing sulfuric acid and an aromatic hydrocarbon in which sulfuric acid is not appreciably soluble to continuously flowagainst each other on the counter-current principle in the presence of an excess of the aromatic hydrocarbon.

' 8. A process for the continuous sulfonation of aromatic hydrocarbons or their derivatives with simultaneous extraction of the sulfonated product, consisting in causing sulfuric acid and an aromatic hydrocarbon in which sulfuric acid is not appreciably soluble to continuously flow against each other on the counter-current principle in the presence of an excess of the aromatic hydrocarbon and continuously removing the resulting sulfonic acid dissolved in said excess ofthe aromatic hydrocarbon.

9. A process for the continuous sulfonation of aromatic hydrocarbons or their derivatives with simultaneous extraction of the sulfonated product consisting in passing a continuous flow of the aromatic hydrocarbon against a continuous flow of sulfuric acid in the presence of an excess of the aromatic hydrocarbon and continuously separating the resulting sulfonic acid from the residual sulfuric acid.-

10. A process for the simultaneous sulfonation of benzene and the extraction of benzene sulfonic acid consisting in causing sulfuric acid and benzene to react upon each other in the presence of an excess of benzene and withdrawing the benzene sulfonic acid' extracted in said excess.

11. A process for the continuous sulfonation of benzene with simultaneous extraction of benzene sulfonic acid consisting in continuously passing an excess of benzene through sulfuric acid and continuously removin the extracted benzene sulfonic acid in sai excess.

12. A process for the continuous sulfonation of benzene with simultaneous extraction of benzene sulfonic acid consisting in passing an excess of benzene through sulfuric acid, continuously withdrawing the' extracted'benzene sulfonic acid in said excess and continuously withdrawing the spent sulfuric acid. i

13. A process for the continuous sulfo- 'nation of benzene with simultaneous extraction of benzene sulfonic acid consisting in causing sulfuric acid and benzene to continuously flow against each other on the counter-current principle in the presence of an excess of benzene.

14. A process for the continuous sulfo- -nation' of benzene with simultaneous extraction of benzene sulfonic acid consisting 1n passing a continuous flow of benzene against a continuous flow of sulfuric acid in the presence of an excess of benzene and continuously separating the resulting benzene sulfonic acid from the residual sulfuric 101 specification.

HAN S In testimony whereof I have signed this I 

